This invention relates to a control for an outboard motor and more particularly to an improved tiller mounted throttle and transmission control for such motor.
In order to facilitate the ease of operation of outboard motors, it has been proposed to attach to the end of the tiller a pivotally supported control handle that contains a controls for operating both the throttle and transmission of the outboard motor. Such attachments, be they accessories or installed originally on the outboard motor, offer considerable ease of operation. However, the type of devices presently utilized are susceptible of improvements in several areas.
For example, both the throttle and transmission control are connected to the appropriate portions of the outboard through bowden wire actuators. Conventionally, there is provided a twist grip throttle control and a pivotally supported shift control with the pivot axis of the shift control extending generally transverselly to the axis about which the throttle control rotates. It is desirable to maintain these controls relatively small and compact. However, it is difficult to obtain the desired degree of movement of the dog clutch of the transmission through conventional pivotally supported shift control levers. That is, the pivotal movement of the lever is relatively small and this small degree of pivotal movement must be transferred into a fairly large degree of reciprocal movement of the clutch for its engagement. This has necessitated rather large assemblies in order to achieve the requisite motion.
It is, therefore, a principal object of this invention to provide an improved outboard motor control that is compact in nature and yet which amplifies the degree of pivotal movement of the shift control lever into axial movement of the wire actuator for the transmission.
It is a further object of this invention to provide an improved transmission control for an outboard motor employing a compact motion amplifying mechanism.
In connection with the throttle and transmission control for outboard motors, it is also desirable to provide a mechanism that ensures that the operator does not attempt to shift from neutral into a forward or reverse drive condition with the engine operating at a high rate of speed. Attempting such transmission shifts when the engine is running at a high rate of speed not only places large loads on the clutch and gear mechanism of the transmission but can cause sudden movements of the watercraft that may be disconcerting to its occupants. However, when a control mechanism is designed to be mounted on the end of the tiller, it is difficult to obtain the necessary interlock arrangement in such a small space.
It is, therefore, a further object of this invention to provide an improved transmission and throttle control for an outboard motor wherein a simplified and compact interlock is provided between the transmission and throttle control.
It is a further object of this invention to provide an outboard motor transmission and throttle control mechanism wherein each mechanism has a motion amplifier and wherein a compact and simple interlock mechanism is provided.
In addition to providing protection against shifting into a forward or reverse mode from neutral with the engine operating at a high rate of speed, many of the interlocks previously proposed also limit the speed at which the engine may be operated in various transmission ratios. For example, the mechanisms may include an arrangement that limits the maximum speed of the engine or maximum throttle opening when operating in neutral. This prevents damage to the engine through running at a high speed with no load present. In addition, the interlocks frequently provide an arrangement that limits the speed of the watercraft when traveling in reverse.
This type of interlock mechanism between the transmission and the throttle, however, means that if the operator wishes to shift into a neutral condition when traveling at a high speed, the operator must first reduce the speed and then effect the shift. This is an unacceptable delay under some conditions.
It is, therefore, a still further object of this invention to provide an improved transmission and throttle control interlock mechanism for an outboard motor that will permit the operator to shift into neutral when the engine is operating at a speed higher than a predetermined speed and at the same time the shift is effected, the engine speed will be reduced.
In connection with the control and as has been previously noted, there is an advantage in providing a motion amplifier between the various controls and the bowden wires which they actuate. Frequently, the throttle control employs a bevel gear transmission for this operation. However, some outboard motors require rotation of the control in one direction to increase the throttle opening while others require rotation of the control in an opposite direction. In order to accommodate this with the previously proposed bevel gear transmissions, it is necessary to shift one of the bevel gears in the control to accomplish the different degree of rotation required for the particular outboard motor. This not only makes construction and assembly difficult but results in a transmission that does not always have smooth feel for the operator.
It is, therefore, a still further object of this invention to provide an improved bevel gear motion amplifier for the throttle control of an outboard motor that easily adapts itself to rotation in either direction for the appropriate outboard motor and also provides a smooth operating feel.
It should be readily apparent from the foregoing description that a desirable control mechanism of this type for an outboard motor incorporates a number of components that are interrelated with each other and which must be assembled in a small area. Also, these components should be installed within a neat appearing housing assembly and this gives rise to substantial problems, particularly when several housing pieces must be connected to each other and wherein the various elements of the control are contained within a cavity formed by the housing pieces.
It is, therefore, a still further object of this invention to provide an improved and simplified housing support arrangement for an outboard motor control.
It is a further object of this invention to provide an outboard motor transmission and throttle control that can be assembled in a manner wherein the spatial relationship between all of the components is easily controlled.